Pulverizing-mill.



I1. 6. CLARK.

PULVERIZING MILL. APPLICATION TILED JUNE 27, 1913.

Patented Feb. 9

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Specification of Letters Patent.

Patented lFeh'Q, 1915.

application filed .Tun 27', 19 1's. Serial no. 776,199.

To all whom it may concern Be it known that I,- JOHN' C. CLARK,'. a citizen of the United States, and resident of Atlanta, Fulton county,- State of Georgia,

5 have invented certain new and useful Improvements in Pulverizing-Mills, of which the following is a specification;

This invention relates to pulverizing mills and morespec'ifically to improvements inthe millshown in my prior Patent No. 1,049,051;

The objects of the invention are to provide a mill which is' simple in construction and which is capable of developing a very powerful centrifugal crushing force. I 5 Another object is to provide 'a mill in which the roll basin is stationary and surrounded bya suitable screen whereby the millis adapted to deliver a finished product.

Another object is to provide a mill 'in which the springs for holding the pressure ring are arranged on the axis of shaft so'as to permit the use of very heavy springs and to avoid excessive compression of the springs due to the movements "of the 5 pressure ring, y

Other objects and the features of novelty will be apparent from the following description taken in connection with the accom panying drawing which is a'transverse sec tion through a pulverizing inill embodying my invention. A a p y Referring to the drawing, 10 indicates the usual basin which is supported on a suitable foundation and carries a track 11 for the balls 12 which do the crushing. As in the case of my prior Patent No.- 1,049,051; I prefer to usethree of the erushing balls 12; these balls being equallv spaced by'means of. the spacing member 13 which is in the forni of a flat plate provided with suitable recesses It in its periphery. to receive the balls, and rotatablyarranged on a pin 15. The plate is supported by means of a thrust bearing 16 and carries on its under side wings'or vanes 5 17 which act as a fan for the'pui'pose of forcing the material out of the'space below the plate .13. I

Arranged above the balls 12 and rest ng thereon is a pressure ring. 18 having arranged on the upper side thereof and in driving connection therewith a spider 19, the radial arms 20 of whichearry at the center a are 21. A raisework 22 is seeiired to the basin 10 and carries suitable bearings 23 and 5 24 for the driving Shaft 25. a an pulthe driving icy '26 is arranged n theshaft 25- and adapted to be connected therewith by means of a clutch 27 of any suitable construction; this ver1zing elements. Arranged on the interior of the housing 29 and spaced therefrom is a suitable screen 31 which is adapted to screen the material and prevent the escape of all except that which has reached the requisite degree of fineness. The pulverized material passes throughthe screen 31 into the surrounding space 32 and is discharged through suitable openings 33 in the basin 10. It will be understood that suitable provision will be made below the mill for receiving the material which passes through the openings 33.

A vertical shaft 34 is supported in bearings 35 and 36; the bearing 35 being carried by the top plate 3.0, and the bearing 36 being carried by a suitable beam or cross member 36 which is adjustably supported on the fraine' work22. A bevel gear 37' is splined on the shaft 34 andvmeshes with a pinion 38 on the driving. shaft 25. The gear 37 is supported by a suitable ball thrust bearing 39, carried on the upper end of the bearing 3.5. The lower end of the shaft 34 carries a claw or clutch member 40 which engages the arms 20 of the spider 19 for the purpose of forming a universal driving connection between the spider and the shaft. Aheavy compression spring 41 is arranged in the cup 21 and carries on its upper end a ball 42 which is arranged in a socket 43 in the lower end of the shaft 34. The shaft'34 has arranged on its upper-end a .ball thrust bearing .44 which c'arries a compressionspring 45, the upper end of the shaft; the ball bearing and the spring being incl'osed by a suitable casing or sleeve 46 secured to the cross beam 36. 1 Above the spring is a plate 47 and a screw 48 which is'provided. with a hand wheel 49 which has threaded engagement ,with the top of the casing 36 and bears on the plate 17', for the purpose of adjusting the pressure which spring 45 exerts on the shaft 34. 4

"Any suitable means for feeding the izi' a terial' to be pulverized may be provided,-and for this purpose I have shown somewhat.

tion of the shaft 34 is transmitted to thepressure ring 18- by means of the clutch member 40 and the spider 19. The pressure exerted by the spring 45 upon the upper end of the shaft 34 is transmitted through the ball and socket bearing 42 and the spring 41 to the spider 19, and from the latter to the pressure ring 18,.thuspressirig the balls 12 against the track 11. The rotation of the pressure ring 18 causes the balls 12 to revolve and travel around in the track 11, the norma-l'surface speed of the balls being substantially the same as that of the surface of the pressure ring which contacts therewith and the revolution of the. balls around in the track 11 i being substantially one half the speed of track 11.

rotation of the shaft 34. When the balls run onto a particle which lifts them the portion of the pressure ring immediately above the ball will be lifted the same amount andthe center of the pressure ring Will be lifted substantially one half of this amount. This motion of the pressure ring is distributed between the springs 41 and 45, each of the springs being compressed sub-. stantially one half of-the movement of the cup 21, or one quarter of the amount of rise of the 'ball. The shaft 34 therefore is also raised one quarter of the amount which the ball islifted. To accommodatethis vertical movement; of the shaft 34 the gear 37 is splined thereon andto accommodate the tilt ng of the pressure ring and spider the ball and socket bearing 42 is'provided. The connection between the clutch 40 and the spider. 19 also permits the tilting of the spider and the pressure ring.

The plate 13 maintains the balls in'a definite s aced relation and revolves at the screen also preventing the escape of the larger particles and returning them to the From the foregoing description it will be apparent that in my improved construction the springs are moved only a very limited extent and therefore it is practical to em ploy very stiff springs and thus secure a heavy crushing force. By revolving the pressure ring the driving mechanism is much simplified and a very efficient and durable construction is provided. The pressure on the balls 12 can be varied by means of the screw 48 and the movement of the screw will be distributed between the springs 41 and 45, and thus equalize the tension of the springs.

While I have illustrated and described what I now believe to be the preferred form of my invention it will be understood that various changes may be made in the details of the construction within the scope of the claims and therefore I do not wish to be limited tothe exact details shown and deand axially movable shaft, an-axially arranged compression spring carried by the pressure ring, a ball and socket bearing between said spring and one end of said shaft, a driving connection between said shaft and the pressure ring permitting the ring to be tilted relative to the shaft and a compression spring at the opposite end of said shaft and opposing said first mentioned spring.

2. In a pulverizing mill, the combination of a roll basin, a plurality of rolls arranged to run therein, a pressure ring, a rotatable and axially movable shaft, a yieldable dri\ ing connection between said shaft and said pressure ring, a. compression spring at the outer end of said shaft and adapted to yieldingly force the pressure ring against the movement and having a slidable connection with said shaft.

3. In a pulverizing mill, the combination of a horizontally arranged roll basin, a plurality ofrolls arranged to run therein, a pressure ring engaging the top of said rolls, a vertical driving shaft, a yielding connection between said shaft and said pressure ring, a compression spring at the top of said shaft, means for varying the tension of said spring, and a horizontally arranged driving Wheel for said shaft held against axial movement and having a sliding connection therewith.

In testimony whereof I aifix my signature in presence of two witnesses.

' JOHN C. CLARK.

Witnesses:

CHAS. T. Biiowiv, GEO. S. OBEAR, J r. 

